1. Field of the Invention
The present invention relates to a display device that allows magnified observation of displayed contents with one eye. In addition, the present invention relates to a display device that is capable of switching nonmagnification display for observing a screen with binocular vision from a position that is a least distance of distinct vision or more apart from the screen and magnification display for observing a screen with one eye from a position closer to the screen than a near point of the eye as a display screen of an information technology device having a compact screen such as a mobile device and a cellular phone.
2. Related Background Art
A magnified observation method for a compact display screen with one eye (monocular vision) of this type has been used for a head mount display (HMD). However, it requires a large optical space for magnified observation and cannot perform nonmagnified observation of one screen with binocular vision at a normal remote distance.
FIG. 7 shows a display device disclosed in Japanese Patent Application Laid-Open No. 10-170860 as the one in which this optical space is eliminated. In the figure, reference numeral 2 denotes an ocular side microlens array (70.8 xcexcm pitch); 3, a transmission liquid crystal display element (76.3 xcexcm pitch); 41, a condensing microlens array (81.8 xcexcm pitch); 42, a collimating microlens array (90 xcexcm pitch); 5, a flat back light; 8, a diffusion hole sheet having openings 9 functioning as micro light-emitting points; S, R, a microlens; P, Q, a transmission liquid crystal display pixel; E, an eyeball of an observer; and O, a pupil of the eyeball. This display device has an ocular optical system including a microlens for guiding irradiated light from each pixel to the eyeball.
However, this is for providing a thin display device with an increased efficiency of utilizing light as an HMD and is not suitable for observation of a screen with binocular vision at a remote distance at all.
That is, if the microlenses 2 are disposed on the surface side of the liquid crystal display element 3 as shown in FIG. 7, when it is attempted to observe the screen with binocular vision from a remote position, a virtual image screen is displayed in a position remote from the surface of the display element by a lens action of the microlenses 2 despite a state in which optical axes of both eyes intersect on the surface of the display element (display surface) due to vergence. Thus, the screen is observed doubly.
Consequently, the display screen cannot be observed favorably at a distance remote from the display surface. In addition, since overlap of the microlenses and pixels is eccentric, crosstalk in which light of neighboring openings enters an opening occurs to deteriorate the image. Further, moirxc3xa9 occurs due to boundaries of the microlenses and pixel boundaries of the display element to deteriorate the image.
FIG. 8 shows a display device disclosed in Japanese Patent Application Laid-Open No. 5-328261 and Japanese Patent Application Laid-Open No. 6-43391. In the figure, reference numeral 81 denotes a field lens; 82, microlenses; 83, an image display device; and E, an eyeball. The display device of this figure can display an image compactly and with a high resolution as an image for an HMD. However, since the field lens is used, a display screen cannot be observed at a remote distance. In addition, since the microlenses are arranged on a surface side of the display device as a part of an ocular optical system, moirxc3xa9 occurs in boundaries of the microlenses and boundaries of pixels. Therefore, the display device is not suitable for screen observation with binocular vision at a remote distance.
As described above, the means for observing a magnified virtual image cannot cope with screen observation at a remote distance.
The present invention has been devised in view of the above and other drawbacks and, it is an object of the present invention to provide a display device with which magnified observation of displayed contents with monocular vision at a close distance can be performed and for which reduction in weight and thickness can be realized.
In addition, it is another object of the present invention to provide a display device with which both the above-described magnified observation with monocular vision at a distance closer than a near point and nonmagnified observation with binocular vision at a remote distance can be performed.
Therefore, according to the present invention, there is provided a display device comprising: self-light-emitting type image displaying means that has pixels arranged two-dimensionally; micro light-emitting points that correspond to each pixel of the image displaying means and exist in a part of the pixel; and a micro optical element that guides irradiated light from each of the micro light-emitting points arranged two-dimensionally, in which optical axes connecting each of the micro light-emitting points and the micro optical element corresponding to the micro light-emitting point substantially intersect in a predetermined point closer than a near point of an eye, and in which the micro optical element is arranged so as to focus a virtual image of the micro light-emitting point corresponding to the micro optical element in a position that is a least distance of distinct vision or more apart from the predetermined point.